Highlight on Eye Assessment

Vision disorders are the fourth most common disability in the United States. Studies show that vision disorders are the most prevalent handicapping condition in children. Because of this, it is recommended that children have a complete eye exami­nation starting at age 3. Both children and adults should have an eye examination every 2 to 3 years up to 60 years of age. Individuals older than 60 years should have yearly eye exam­inations.

Individuals who have risk factors for eye disorders should have an eye examination every year. Examples of risk factors are diabetes and hypertension.

Visual acuity is considered normal for the various age- groups if it falls within the following values:

Newborn 20/500

Child 1 month to 6 months 20/200 to 20/90

Child 6 to 12 months 20/60

Child 12 to 18 months 20/40

Child 2 to 3 years 20/30

Child 3 to 18 years 20/20

Adult 18 years or older 20/20

Legal blindness is defined as a visual acuity measurement of 20/200 or less in both eyes with the use of corrective lenses.

The term colorblind is not an accurate term to describe an individual with abnormal color vision because the inability to distinguish any colors at all is extremely rare. Most individuals with a color vision abnormality are unable to distinguish cer­tain hues of color, such as red and green. Therefore a better term is "color vision defect."

Defective color vision is usually congenital. It is found in 8% of men and 5% of women.

Studies show that there is no significant correlation be­tween defective color vision and increased automobile acci­dents. The majority of drivers who have a color vision defect are able to distinguish traffic lights by the different light inten­sities and by the position of the light on the traffic signal.